Gear train arrangements

ABSTRACT

Gear train arrangements for transmitting a power from a driving source to a driven member at more than three speeds in one direction and another speed in the opposite direction, the gear train arrangements using basically three planetary gear sets and at least five friction elements such as clutches and brakes which are selectively actuated to selectively engage the rotary members of the three planetary gear sets to deliver an output power at the above said speeds. The gear train arrangements are specifically adapted for use in an automatic transmission system of a motor vehicle using a torque converter or fluid coupling.

United States Patent 7 [191 [111 3,823,622 [45] July 16, 1974 Mori et al.

GEAR TRAIN ARRANGEMENTS Inventors: Yoichi Mori, Yokohama; Nobuo Okazaki, Chigasaki; Kunio Ohtsuka; Tetsuya Iijima, both of Tokyo, all of Japan Assignee: Nisson Motor Company, Limited,

Yokohama, Japan Filed: Sept. 13, 1972 Appl. No; 288,551

Related US. Application Data Division of Ser. No. 30,496, April 21, 1970, Pat; No. 3,701,293.

Foreign Application PriorityData Apr. 30, 1969 Japan 44-32685 US. Cl. 74/759 'Int. Cl. Fl6h 57/10 Field of Search 74/759 References Cited- UNITED STATES PATENTS 3/1951. Winther 74/759 2,917,951 12/1959 Aschauer ..74/759X Primary Examiner-A. T. McKeon Attorney, Agent, or Firm-Depaoli & OBrien 5 7 ABSTRACT Gear train arrangements for transmitting a power from a driving source to-a driven member at more than three speeds in one direction and another speed in the opposite direction, the gear train arrangements using basically three planetary gear sets and at least five friction elements such as clutches and brakes which are selectively actuated to selectively engage the rotary members of the three planetary gear sets to deliver an output power at the above said speeds. The gear train arrangements are specifically adapted for use in an automatic transmission system of a motor vehicle using a torque converter or fluid coupling.

1 Claim, 37 Drawing Figures PATENIED JUL 1 8 I974 EE on HF 15 Fig. 4 B1 33 C2 2 94 B3 .H/ "*TT INPUT OUTPUT Fig-4av Y PATENTED 1 61974 Ill 823 .622

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' SHEET 0911f 15 IO ll INPUT(F) OUTPUT |NPUT(R) M3 7 Hg 90 7 L M N O PATENTED 3,823,822

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GEAR TRAIN ARRANGEMENTS This is a division of application Ser. No. 30,496 filed April 21, 1970, now Pat. No. 3,701,293.

This invention-relates to gear train arrangements for a transmission system of a motor vehicle and, more particularly, to gear train arrangements of planetary gear type adapted to provide basically four forward and one reverse vehicle speeds.

A usual gear train arrangement using a planetary gear system is made up of a combination of one or more, similar or different, planetary gear sets each having one or more planet pinions and is operated through actuation of friction elements such as clutches and brakes which are arranged to attain a desired combination of gear ratios. Typical of such gear train arrangement is I the one that uses three simple planetary gear sets which are combined together to provide three forward and one reverse vehicle speeds. (It may be noted that the term simplef planetary gear set as herein used is intended to refer to a planetary gear set having a single planet pinion.)

Foremost of the practical requirements of a gear train arrangement to attain an increased number of vehicle speeds is a wide selection of the combinations of gear ratios, which requirement, however, is reflected by an increased number of component'parts of the gear train arrangement and complicated gear shifting operations.

In order that the gear train be snugly accommodated within a limited space in the transmission system, every component of the planetary gear system should be as small in dimensions as possible. From the view point of production economy,.moreover, it is desired that the number of the component parts of the gear train be reduced to a minimum and that the parts corresponding in function be fabricated to be common in geometry to one another so as to permit of quantity production. Another important requirement of .the gear train of a transmission system is the ease of gear shifting operations.

It is, therefore, an object of the invention to provide gear train arrangements adapted to provide basically four forward and one reverse vehicle speeds. 7 Another object is to provide gear train arrangements providing essentially four forward and one reverse vehicle speeds with wide selection of the combinations of gear ratios.

Still another object is to provide gear train arrangements providing four, or even more, forward and one reverse vehicle speeds, which arrangements are constructed with a practically minimum number of component parts and nevertheless can provide practically any desired combination'of gear ratios.

Still another object-is to provide gear train arrangements that are suited for quantity production.

Still another object is to provide gear train arrangements providing four, or even more, forward and one reverse vehicle speeds with utmost ease of gear shifting operations.

In order to achieve these and other objects, the invention proposes to use various combinations of basically three substantially identically sized planetary gear sets which are operated by'means of two or three clutches and two or three brakes. The gear train arrangements using such combinations can be readily modified with incorporation of additional minor arrangements into those providing five or six forward and one reverse vehicle speeds.

In the drawings:

F IGS. 1 to 8 are sectional views schematically showing various preferred embodiments of the invention, each of which embodiments uses three planetary gear sets with two clutches and three brakes to provide four forward and one reverse vehicle speeds;

FIG. 9 is similar to FIGS. 1 to 8 but shows other embodiment" using three planetary gear sets with three clutches and two brakes to provide four forward and one reverse vehicle speeds;

' FIGS. 10, l'1,'and 12 are views illustrating still other embodiments using three planetary gear sets with three clutches and three brakes to provide'four forward and one reverse vehicle speeds;

FIG. 13 is a view illustrating still another embodiment using four (including one auxiliary) planetary gear sets with three clutches and four brakes to provide four forward and one reverse vehicle speeds;

FIG. 14 is aview illustrating still another'embodiment using three planetary gear sets with three clutches and threebrakes to provide five forward and one reverse vehicle speeds;

FIG. 15 is a view illustrating still another embodiment using four (including one auxiliary) planetary gear sets with two clutches and three brakes to provide FIGS. la to 16a are diag rams each showing the different revolution speeds of the individual rotary members of the planetary gear sets used in the embodiment illustrated in the corresponding figure out of FIGS. 1 to 16; and

FIGS. lb, 4b, 6b, 7b, 8b, 9b and 1012 are views-each showing a modification of the embodiment illustrated in the corresponding figure without the subscript.

Corresponding reference numerals and characters represent like members in all the figures.

It may be noted in regard to the drawings that only the upper half of each gear train arrangement is herein shown for simplicity of illustration because 'the gear train arrangement is generally symmetrical with respect to the input and output shafts.

First referring to FIG. 1, the gear train according to one embodiment of the invention is, as customary, connected at one end with an engine through an input shaft 10 and a torque converter or fluid coupling (not shown) and at the other end with a differential (not shown) through an output shaft 11 of the transmission system.

The gear train as shown includes a first, second andthird planetary gear sets l2, l3 and 14, all of which are constructed as simple planetary gear sets which are fabricated to be substantially identical in geometry with each other.

The first planetary gear set 12 comprises an outer ring gear R a planet pinion P meshing with the outer ring gear, and a sun gear 5, meshing with the planet pinion. The second planetary gear set 13 similarly com- 3. prises an outer ring gear R a planet pinion P meshing with the ring gear, and a sun gear S meshing with the planet pinion. The third planetary gear set 14 also similarly comprises an outer ring gear R a planet pinion P meshing with they ring gear, and a sun gear 5;, meshing with the planet pinion. The planet pinions P,, P and P are carried on and revolved by pinion carriers l5, l6 and 17, respectively. The ring gears, pinion carriers and sun gears are all rotatable about a common axis which is in line with the axes of the pinion carriers. More detailed discussion on the construction and motions of the. planetary gear set per se is herein omitted because they are well known in the art.

The ring gear R, of the first planetary gear set 12 is constantly connected to and rotatable with the planet pinion P of the second planetary gearset 13 through the pinion carrier which forms part of a drum, 18. The sun gears S, and S of the first and second planetary gear sets 12 and 13, respectively, are constantly'connected to and rotatable with the input shaft of the transmission through mechanical linkages 19 and 20, respectively. The ring gear R is constantly connected to and rotatable with the sun gear 5,, of the third planetary gear set 14 through a drum 21. The pinion carrier power to the differential not shown).

The pinion carrier 15 of the planet pinion P, is connected to a first band brake B, which, when applied, holds the pinion carrier 15 stationary. The drum 18 interconnecting the ring gear R, and pinion carrier 16 coacts with a second band brake B2 which, when applied, holds both the ring gear R, and pinion carrier 16 stationary. The drum 21 interconnecting the ring gear R and sun gear 5;, coacts with a third hand brake B, which, when applied, holds both the ring gear R and sun gear S, stationary.-

Two clutches C, and C are provided to selectively connect the ring gear R to the drum 21 and the input shaft 10, respectively.

Now, it is well known in the art that, assuming the revolution speeds of'a ring gear, sun gear and pinion carrier of a given planetary gear set are Nr, Ns and Np, respectively, and the ratio of the number of teeth of the sun gear to the number of teeth of the ring gear is a, then the following equation holds:'

(a l)'Np Nr OZNS.

Thus, for the planetary gear sets l2, l3 and 14, the following equations can be derived:

(a, l)-Np, Nr, a,-Ns,,

(a, l)-Np Nr,, a -Ns and (a, l )'Np Nr,, a -Ns where the subscripts l, 2 and 3 represent the first, second and third planetary gear sets l2, l3 and 14, respectively.

In consideration of the constant connections between some of the rotary members of the planetary gear sets, the following equations hold:

NS Nsg, Nr, NPQ, and Nrg N83.

The speeds Ns, and Np, are equal to the revolution speeds of the input and output shafts l0 and 11, respectively.

These mathematical relations between-the revolution speeds of the individual rotary members of the planetary gear sets can be graphically illustrated in F 10. la, wherein points L, M and N are given on a line OO' in such a manner that the followingrelations are maintained:

OL/LM 11,, ON/NO a e d o'L/ o a Thus, the points 0, L, M, N and 0 stand for the relations. between those individual rotary members of the planetary gear sets which are respectively shown below these points. The speed vector of each rotary member Ns N73 and Np, 0.

In this condition, the gun gear S, is rotated directly by the input shaft 10 with the pinion carrier 15 held stationary so that the ring gear l i fa nd the pinion carrier 16 of the planet pinion P rotate at a speed corresponding to a vector NN, in FIG. la.-With the sun gear 5, rotating with the input shaft 10, the ring gear R and the sun gear 5;, rotate at a'speed corresponding to a vector OO,. The ring gear R rotating with the input shaft and the sun gear 8;, rotating at a speedcorresponding i/ n 1 In/[1 1211, lau m.

When the vehicle speed is to be shifted from the firsl to the second speed, then the first brake B, is released and instead the second brake B isapplied with the second clutch C kept coupled. Thus:

, Nr, Np, 0. With the brake B applied, the pinion carrier 16 is 4 held stationary and the sun gear S Yrotates with the When the speed is to be shifted from the second to the third speed, the second brake B is released and instead the third brake B applied with the second clutch C kept coupled. Thus:

With the brake 8,, applied and the clutch C coupled, the sun gear 8;, is held stationary and the ring gear R rotates with the input shaft 10 so that the pinion carrier 17 of the planetpinion P rotates at a speed correspending. t a yeswtyrh sh. sr yislesasear at o to establish the third forward speed.

The gear ratio for the third speed-is thus expressed as:

these conditions are tabulated in Table I. wherein the sign refers to that the related clutch or brake is actuated and the sign refers to that the clutch or brake is kept released. The gear ratios indicated in the 5 parentheses are derived on the assumption that or a a 0.45. (This will apply to all the tables which are [WI/N63 l hereinafter presented.) I in order to streamline the shifting between the first f 3 i i b g i 39 g 3 :2 and second speeds, a one-way clutch 23 may be pro-' en d I: e 5 f E k i vided on the planet carrier of the first planetary gear 215 e w] e p c u C 2 ep set l2 ,as illustrated in FIG. 1b, if desired. V I It will be appreciated that the gear train shown in FIGS. 1 and 1b are suited to provide ease of gear shiftz 's z- Y 15 ing operations because the gear ratios can be changed merely by releasing only one of the clutches and brakes With the brakes B B and 8;, released and the and t attng ano her we q lheme clutches C1 and C2 c upl d, all h p a tary g s ts FIG. 2 illustrates another form of the gear train acrotate with the input Shaft SO a t tevolutlon speed cording to the invention. The gear train is constructed of the pinion carrier 17 of the planet pinion P is equal so as to provide four forward and one reverse speeds to the Speed of the input Shaft, as indicated by a Vector with use of three identical planetary gear sets 12, 13 L1 in FIG. 1a. and 14 which are operated by two clutches C and C The gear ratio for the fourth speed attained in this d three ba d h h Bl? g d g manner thus expressed as: The first clutch C is linked on the one hand with the N? l N 1 input shaft 10 of the transmission and on the other with 1 l a the ring gear R, of the first planetary gear set 12. The When the vehicle is to be moved backwardly, the first Second m l Winch also'lmked the mput clutch C is coupled and the second brake B applied. Shaft lmked i both the Sun gears S1 and S2 of Thus; w the first and second planetary gear sets 12 and 13, re-

' spectively, through a drum 24 for the first band brake [W2 Nra and Npz 8,. The sun gears S and S are as a result constantly connected together and rotatable with each other. The wi the brake B2 applied and the Sun gear 5 planet pinion P of the first planetary gear set 12 18 contotating With the input h ft 0 the ring gear R2 and the stantly connected to and rotatable with the ring gear R sun gear S rotate at a speed corresponding to a vector offhe Second Planetarys gear Set Sun gear S3 of the 00;. since ill this instance, the clutch cl is coupled, thlrd k s gear Set a Output Shaft 11 9 the the ring gear R also rotates at a speed equal t6 h transmission through the p1nioncarrierl5 and an inter- Speed f h ring gear R2 and Sun gear 5 Both the ring mediate shaft 25. The planet pinion P of the second gear R and sun gear S rotating at the speed corre- 4 planetarygear set 13 IS constantly connected to and r0- sponding to 0'02, the planetary gear set 14 rotates i tatable Wlth the Pla et ptnton P of the third planetary its entirety at this speed. The output shaft 11 is thus rogear Set 14 through the pmlon Gamers 16 and 17 wh'ch tated at a speed Corresponding to LLT in direction form part of a drum 26 for the second band brake 8 Opposite to the rOtathm of the input Shaft The ring gear R of the third planetary gear set 14 IS The gear ratio for the reverse speed thus established Connected to a drum 27 for the thrd band brake is thus expressed as: The conditions of the clutches and the brakes for the N /N 1 different vehicle speeds and the gear ratios attained in these conditions are tabulated in Table II; the gear ra- The conditions of the clutches and brakes for the diftios are calculated in a manner similar to that discussed ferent vehicle speeds and the gear ratios attained under in connection with the geartrain of F IQ. 1,

, TABLE I t c 0, B. a, na Gear RfltiOS Forward: l a V J. lst 1w as! lash +0) (2.88)

f l a 2nd t-21+ (1.82)

3rd I+ 1+0; (1.4-5)

4th l (1.00)

l Rev (-2.22)

' TABLE II l I Bl Bu ll Gear Ratios Forward lst l+a,+:l (2.4-)

E BELL l 2nd 1+ +0) (1.82)

3rd 1+a, 1.45

4th 1 t (1.00)

Rev (-2.22)

When the first tarps rd speedjsselectedfthe clutch C, is coupled and the brake B applied. In this instance, the operations of the individual rotary members will be easily understood if it is assumed that the output shaft 11 is first rotated to impart a rotational effort to the input shaft 10, conversely to the actual operation. Thus, if the output shaft 11 is rotated at a speed corresponding to a vector AA, in FIG. 2a, then the ring gear R and the pinion carrier 15 of the planet pinion P, will rotate at the same speed as the output shaft 11. With the brake B applied, the planet pinion P is held stationary so that the sun gears S and S, rotate at a speed corresponding to a vector OO,. Such rotation of the sungear S, and the pinion camensrwhich revolves at a speed equal to the revolution speed of the output shaft 11) will dictate the speed at which the ring gear R, of the first planetary gear set 12 rotates as representated by a vector 00, in FIG. 2a. The driving force is actually carried to the input shaft 10,

not to the output shaft 11, so that the flow of rotation is exactly inverse from that discussed above. Thus, it is apparent that the first speed corresponds with the vector AA, in FIG. 2a.

When the speed is shifed from the first to the second speed, then the brake B is released and the brake B is applied with the clutch C, kept coupled. Here, it is also assumed that the driving force is initially transshaft Hit, a speed corresponding tov the vector T1,,

the sun gears S and S rotate at a speed corresponding to the vector oG'.'fi1"pTant"pinion PP] i s rotated with the pinion carrier 15 rotating with the output shaft 11 so that the ring gearll, will rotate ata speed corre spondingto the vector GGYiKFIG. 2a. The actual operations of the planetary gear sets are exactly converse from those discussed above but, anyway, it is apparent that the second speed corresponds to the vector LL in FIG. 20.

When the speed is shifted from the second to the third speed, the brake ,B, in lieu of the brake B is now applied with the clutch C, kept'coupled, so that the sun gears S, and S, are held stationary and the ring gear R,

rotates with the input shaft 10. The pinion carrier 15 supporting the planet pinion P,, therefore, rotates at-a speeds corresponding to a vector LL, providing a gear ratio for the third forward speed.

When the speed is further shifted up from the third to he fourth 5dai1 the bralies are released and the clutches are coupled so that the first planetary gear set 12 rotates in its entirety at the same speed as the input shaft 10. The speed of the input shaft 10 is in this manner transferred to the output shaft 11 as it is.

For effecting the reverse movement of thevehicle, the clutch C is coupled and the brake B applied. The sun gear S now rotates with the input shaft 10 with the pinion carrier 15 heltlstation a ry so that the ring gear R rotates at a speed corresponding to a vector LL, which provides a gear ratio to establish the reverse speed.

It will now be appreciated that the gear train of FIG. 2 is, similarly to that of FIG. 1, adapted to provide ease of gear shifting operations because the gear ratios can be changed merely by releasing only one of the clutches andxfal ces. and act ua t i riganother one of them.

FIG. 3 illustrates still another form of the gear train according to the invention constructed to provide, four forward and one reverse speeds. The gear train also has three identical planetary gear sets 12,13 and 14-with two clutches C, and C and threebrakes B,, B and B as shown. v p

The first clutch C, is linked on one side with the input shaft 10 and on the other with the ring gearR, of the first planetary gear set 12 througha drum 28 of the first band brake 8,. The second clutch C is linked on one side with the input shaft 10 and on the other with the sun gears 8,, S andS of the first, second and third planetary gear sets l2, l3 and 14, respectively, through an intermediate shaft '29. The sun gears S,, S -and S, are thus constantly connected to each other and rotatable with the input shaft 10 when the clutch C is coupled. The pinion carrier 15 of the planet pinion P, of the first planetary gear set 12 is constantly connected to and rotatable with the ring gear R of the second planetary gear set 13 through a drun '30'for the second hand brake B The pinion carrier 16 of the planet pinion P of the second planetary gear set 13 is constantly connected to and rotatable with the ring gear R of the third planetary gear set' 14 and is linked with the third brake B, through a drum 31. The pinion carrier 17 of the planet pinion P, of the third planetary gear set 14 is connected to the output shaft 11. A one-waybrake 32 is provided to prevent the pinion carrier 16 and ring gear R, from rotating in a direction opposite'to the rotation of the input shaft 10. 

1. A gear train comprising:
 1. an input shaft;
 2. an output shaft;
 3. a first planetary gear set having a ring gear, a pinion carrier carrying a planet pinion meshing with the ring gear, a sun gear meshing with the planet pinion, the sun gear being connected to said input shaft;
 4. a second planetary gear set having a ring gear, a pinion carrier carrying a planet pinion meshing with the ring gear and a sun gear meshing with the planet pinion, the sun gear being connected to the ring gear of said first planetary gear set;
 5. a third planetary gear set having a ring gear, a pinion carrier carrying a planet pinion meshing with the ring gear and a sun gear meshing with the planet pinion, the pinion carrier being connected with the ring gear of said second planetary gear set and said output shaft, the sun gear being connected with the sun gear of said second planetary gear set;
 6. first clutch means for engaging said input shaft with the ring gear of said first planetary gear set, the sun gears of said second and third planetary gear sets during operation of fourth forward and reverse speeds;
 7. second clutch means for engaging said input shaft with the ring gear of said third planetary gear set during operation of first, second, third and fourth forward speeds;
 8. first brake means for anchoring the pinion carrier of said first planetary gear set during operation of second forward speed;
 9. second brake means for anchoring the ring gear of said first planetary gear set, the sun gears of said second and third planetary gear sets during operation of third forward speed; and
 10. third brake means for anchoring the pinion carrier of said second planetary gear set during operation of first forward and reverse speeds.
 2. an output shaft;
 3. a first planetary gear set having a ring gear, a pinion carrier carrying a planet pinion meshing with the ring gear, a sun gear meshing with the planet pinion, the sun gear being connected to said input shaft;
 4. a second planetary gear set having a ring gear, a pinion carrier carrying a planet pinion meshing with the ring gear and a sun gear meshing with the planet pinion, the sun gear being connected to the ring gear of said first planetary gear set;
 5. a third planetary gear set having a ring gear, a pinion carrier carrying a planet pinion meshing with the ring gear and a sun gear meshing with the planet pinion, the pinion carrier being connected with the ring gear of said second planetary gear set and said output shaft, the sun gear being connected with the sun gear of said second planetary gear set;
 6. first clutch means for engaging said input shaft with the ring gear of said first planetary gear set, the sun gears of said second and third planetary gear sets during operation of fourth forward and reverse speeds;
 7. second clutch means for engaging said input shaft with the ring gear of said third planetary gear set during operation of first, second, third and fourth forward speeds;
 8. first brake means for anchoring the pinion carrier of said first planetary gear set during operation of second forward speed;
 9. second brake means for anchoring the ring gear of said first planetary gear set, the sun gears of said second and third planetary gear sets during operation of third forward speed; and
 10. third brake means for anchoring the pinion carrier of said second planetary gear set during operation of first forward and reverse speeds. 